Process analysis for magnetic pulse welding of similar and dissimilar material sheet metal joints

Psyk, Verena; Scheffler, Christian; Linnemann, Maik; Landgrebe, Dirk

doi:10.1016/j.proeng.2017.10.787

Cited by 36 publications

(23 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If collision parameters are appropriate, a so-called jet effect removes potential oxide layers and other surface contaminations from the collision zone. Supported by the contact pressure, the resulting clean and highly reactive surfaces form a metallically bonded joint [14]. Strain rates in this process variant can locally reach values in the range of 10 5 /s up to 10 6 /s.…”

Section: High-speed Technologiesmentioning

confidence: 99%

Determination of Material and Failure Characteristics for High-Speed Forming via High-Speed Testing and Inverse Numerical Simulation

Psyk

Scheffler

Tulke

et al. 2020

JMMP

Self Cite

View full text Add to dashboard Cite

In conventional forming processes, quasi-static conditions are a good approximation and numerical process optimization is the state of the art in industrial practice. Nevertheless, there is still a substantial need for research in the field of identification of material parameters. In production technologies with high forming velocities, it is no longer acceptable to neglect the dependency of the hardening on the forming speed. Therefore, a method for determining material characteristics in processes with high forming speeds was developed by designing and implementing a test setup and an inverse parameter identification. Two acceleration concepts were realized: a pneumatically driven one and an electromagnetically driven one. The method was verified for a mild steel and an aluminum alloy proving that the identified material parameters allow numerical modeling of high-speed processes with good accuracy. The determined material parameters for steel show significant differences for different stress states. For specimen geometries with predominantly uniaxial tensile strain at forming speeds in the order of 10 4 -10 5 /s the determined yield stress was nearly twice as high compared to shear samples; an effect which does not occur under quasi-static loading. This trend suggests a triaxiality-dependent rate dependence, which might be attributed to shear band induced strain localization and adiabatic heating.Despite these advantages, the corresponding technologies, which are often referred to as high-speed forming, impulse forming or high-energy-rate-forming (HERF) [2] have not yet achieved a great industrial breakthrough. Reasons for this are lacking process knowledge and reliable process design strategies. When considering conventional forming processes, it is possible to assume a close approximation of quasi-static conditions, and numerical process design and optimization as state of the art. By contrast, the analysis and design of manufacturing processes with high forming speeds has hitherto been strongly experimental. Numerical considerations are helpful to investigate fundamental relationships, but often only qualitative interpretation is possible. One reason for this is that material parameters are hardly available at the process-specific high strain rates in the range of 10 s −1 up to 10 5 s −1 or even more. The identification of these parameters is complicated, because in addition to the influencing factors known from quasi-static conditions such as temperature and strain, the plastic flow and failure behavior of many materials strongly depends on the strain rate. Therefore, neglecting forming heat, as well as a strain rate-dependent hardening is no longer acceptable. Providing a method for determining reliable material and failure characteristics for the simulation of high-velocity forming, cutting, and joining processes will therefore contribute to making technological, economic, and ecological advantages of these processes exploitable in industrial production.

show abstract

Section: High-speed Technologiesmentioning

confidence: 99%

Determination of Material and Failure Characteristics for High-Speed Forming via High-Speed Testing and Inverse Numerical Simulation

Psyk

Scheffler

Tulke

et al. 2020

JMMP

Self Cite

View full text Add to dashboard Cite

show abstract

“…After overcoming the initial gap, flyer and target are involved in a high-speed collision. If the collision parameters (impact velocity and impact angle) lie within a process window, which is specific for the material combination, an impact welded joint is generated [11]. In contrast to classic welding techniques, magnetic pulse welding forms the joint at room temperature without significant heating of the parts, thus avoiding temperature-induced problems such as thermal softening or the formation of continuous intermetallic or oxidic phases deteriorating the weld quality.…”

Section: Motivation and Principle Of Incremental Magnetic Pulse Weldingmentioning

confidence: 99%

“…In particular, in this reference a one millimetre thick flyer sheet made of EN AW-1050 was welded to a two millimetre thick target sheet made of Cu-DHP. Suitable process parameters guaranteeing high weld quality were chosen based on the results of a detailed study quantifying the influence of important adjustable process parameters on quality criteria of the resulting weld such as transferable force, electrical and thermal conductivity, and width of the weld seam [11]. Specifically, the following values were chosen:…”

Section: Motivation and Principle Of Incremental Magnetic Pulse Weldingmentioning

confidence: 99%

“…Another important evaluation criterion for joints produced by magnetic pulse welding is the extension of the welded area, which is directly related to the conductivity of the weld and the force, which can be transferred via the weld [11]. Obviously, it is desirable to maximise the extension of the welded area.…”

Section: Microstructural Investigations Of the Welded Specimensmentioning

confidence: 99%

See 1 more Smart Citation

Incremental magnetic pulse welding of dissimilar sheet metals

et al. 2018

Self Cite

View full text Add to dashboard Cite

Magnetic pulse welding is a solid state welding process using pulsed magnetic fields resulting from a sudden discharge of a capacitor battery through a tool coil in order to cause a high-speed collision of two metallic components, thus producing an impact-welded joint. The joint is formed at room temperature. Consequently, temperature-induced problems are avoided and this technology enables the use of material combinations, which are usually considered to be non-weldable. The extension of the typically linear weld seam can easily reach several hundred millimetres in length, but only a few millimetres in width. If a larger connected area is required, incremental or sequential magnetic pulse welding is a promising alternative. Here, the inductor is moved relative to the joining partners after the first weld sequence and then another welding process is initiated. Thus, the welded area is extended gradually by arranging multiple adjacent weld seams. This paper demonstrates the feasibility of incremental magnetic pulse welding. Furthermore, the influence of important process parameters on the component quality is investigated and evaluated in terms of geometry and micrographic analysis. Moreover, the suitability of different mechanical testing methods is discussed for determining the strength of the individual weld seams.

show abstract

“…For example, reports about the presence or absence of intermetallic phases are contradictory, and no general agreement has been achieved on the related question of whether the magnetic pulse welding process occurs completely in the solid state or not [5,7,8]. Due to this limited understanding, extensive experiments are typically necessary for each desired material combination, particularly to establish valid process windows for successful welding [9,10]. In explosive welding, these process win-dows are often expressed as a combination of either the impact velocity v imp , or the velocity of the contact line between the joint metals v c , and the collision angle α [1].…”

Section: Introductionmentioning

confidence: 99%

On the microstructure and the origin of intermetallic phase seams in magnetic pulse welding of aluminum and steel

Böhme

Sharafiev

Schumacher

et al. 2019

Materialwissenschaft Werkst

View full text Add to dashboard Cite

The microstructure of aluminum‐steel compounds fabricated by magnetic pulse welding are investigated. Electron backscatter diffraction, energy dispersive x‐ray spectroscopy and scanning electron microscopy revealed the existence of several different phases along the weld seam. While one layer could be identified as aluminum solid solution, a very thin layer close to the steel side of the compound eluded detailed characterization by scanning electron microscopy techniques. Transmission electron microscopy and selected area electron diffraction investigations of this layer revealed a mix of nanocrystalline and amorphous parts. When ambient pressure was reduced to 1 mbar during welding, no interlayers were observed in the samples. This suggests that the interlayers are precipitates of the jet that is formed during conventional impact welding.

show abstract

Process analysis for magnetic pulse welding of similar and dissimilar material sheet metal joints

Cited by 36 publications

References 5 publications

Determination of Material and Failure Characteristics for High-Speed Forming via High-Speed Testing and Inverse Numerical Simulation

Determination of Material and Failure Characteristics for High-Speed Forming via High-Speed Testing and Inverse Numerical Simulation

Incremental magnetic pulse welding of dissimilar sheet metals

On the microstructure and the origin of intermetallic phase seams in magnetic pulse welding of aluminum and steel

Contact Info

Product

Resources

About